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dc.contributor.authorWaters, Christopher L.  Concept link
dc.contributor.authorSims, Kenneth W. W.  Concept link
dc.contributor.authorSoule, Samuel A.  Concept link
dc.contributor.authorBlichert-Toft, Janne  Concept link
dc.contributor.authorDunbar, Nelia W.  Concept link
dc.contributor.authorPlank, Terry  Concept link
dc.contributor.authorPrytulak, Julie  Concept link
dc.contributor.authorSohn, Robert A.  Concept link
dc.contributor.authorTivey, Maurice A.  Concept link
dc.date.accessioned2013-12-05T15:54:36Z
dc.date.available2014-10-22T08:57:20Z
dc.date.issued2013-08-01
dc.identifier.citationGeochemistry, Geophysics, Geosystems 14 (2013): 2547–2574en_US
dc.identifier.urihttps://hdl.handle.net/1912/6341
dc.descriptionAuthor Posting. © American Geophysical Union, 2013. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry, Geophysics, Geosystems 14 (2013): 2547–2574, doi:10.1002/ggge.20134.en_US
dc.description.abstractThe ridge crest at 9°N–10°N East Pacific Rise (EPR) is dominated by overlapping lava flows that have overflowed the axial summit trough and flowed off-axis, forming a shingle-patterned terrain up to ∼2–4 km on either side of the axial summit trough. In this study, we employ 230Th-226Ra dating methods, in conjunction with geochemistry and seafloor geological observations, in an effort to discern the stratigraphic relationships between adjacent flows. We measured major and trace elements and 87Sr/86Sr, 143Nd/144Nd, 176Hf/177Hf, and 238U-230Th-226Ra for lava glass samples collected from several flow units up to ∼2 km away from the axial summit trough on the ridge crest at 9°50′N EPR. Statistical analysis of the 238U-230Th-226Ra data indicates that all but one measured sample from these flows cannot be resolved from the zero-age population; thus, we cannot confidently assign model ages to samples for discerning stratigraphic relationships among flows. However, because groups of samples can be distinguished based on similarities in geochemical compositions, particularly incompatible element abundances with high precision-normalized variability such as U and Th, and because the range of compositions is much greater than that represented by samples from the 1991–1992 and 2005–2006 eruptions, we suggest that the dive samples represent 6–10 eruptive units despite indistinguishable model ages. Geochemical variability between individual flows with similar ages requires relatively rapid changes in parental melt composition over the past ∼2 ka, and this likely reflects variations in the relative mixing proportions of depleted and enriched melts derived from a heterogeneous mantle source.en_US
dc.description.sponsorshipThis study was funded by NSF OCE-0623838 to K.W.W. Sims and S.A. Soule and NSF OCE-0527053 to K.W.W. Sims. J. Blichert-Toft acknowledges financial support from the French Agence Nationale de la Recherche (grant M&Ms – Mantle Melting – Measurements, Models, Mechanisms).en_US
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dc.format.mimetypeapplication/vnd.ms-excel
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dc.language.isoen_USen_US
dc.publisherJohn Wiley & Sonsen_US
dc.relation.urihttps://doi.org/10.1002/ggge.20134
dc.subjectU-seriesen_US
dc.subjectGeochemistryen_US
dc.subjectGeochronologyen_US
dc.subjectEast Pacific Riseen_US
dc.titleRecent volcanic accretion at 9°N–10°N East Pacific Rise as resolved by combined geochemical and geological observationsen_US
dc.typeArticleen_US
dc.description.embargo2014-02-01en_US
dc.identifier.doi10.1002/ggge.20134


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